For the AOWFS and the LOWFS to work then the elevation is limited to Zenith distances ≤40°, with a possibility to reach Zenith distances of 50° with a lower performance. The wavefront sensors are designed to reach peak performance on point sources and the performance decreases by observing extended objects, more details can be found at Extended Objects.

It should be noted that a target fainter than the I-band magnitude of 9.0 and Zenith distance >40° is not feasible.